RESUMO
N-Nitrosoephedrine (NEP) and N-nitrosopseudoephedrine (NPEP) were synthesised at 5 degrees C using different concentrations of various acids. The reaction with acetic acid gave the highest yield (85%) of N-nitrosamine. Ephedrine and pseudoephedrine were reacted with nitrite under physiological conditions (37 degrees C, pH 1-3) to form NEP and NPEP. The yield of NEP, which is a known carcinogen, and NPEP were the highest (18.5%) at pH 2. Aqueous and alcoholic extracts of Ephedra foliata (100 g dry wt), nitrosated under physiological conditions, produced 0.77 mg and 8.3 mg, respectively, as total nitrosamines. This indicated the potential of the nitrosamine formation from the plant extracts specified.
Assuntos
Efedrina , Nitrosaminas/síntese química , Extratos Vegetais , Plantas Medicinais , Fenômenos Químicos , Química , Nitrito de SódioRESUMO
Dissolution and absorption rates (in vitro); clearance from blood and elimination rates of N-nitrosoephedrine (NEP) and N-nitrosopseudophedrine (NPEP) in mice were determined. The two isomers obeyed first-order kinetics and from the slope of the regression line, the rate constant for each study was obtained. These constants were 0.023, 0.038 min-1 (dissolution); 0.192, 0.225 h-1 (stomach absorption); 2.898, 1.980 h-1 (intestinal absorption); 0.33, 0.55 h-1 (blood clearance) and 0.373, 0.393 h-1 (elimination from whole animal) of NEP and NPEP, respectively, and were tested by Student's t-test. Significant differences in the dissolution, absorption and blood clearance rates of NPEP from those of NEP have been observed (P less than 0.05-0.01). These differences are expected to exert their influence on the metabolic rates and the carcinogenic and/or spectral properties of NEP and NPEP, in a related pattern.
Assuntos
Nitrosaminas/farmacocinética , Animais , Dieta , Absorção Intestinal , Taxa de Depuração Metabólica , Camundongos , SolubilidadeRESUMO
Urachal cyst is rather a rare lesion with interesting and different ways of presentation. More urachal cysts are being shown by ultrasound and computed tomography, and their criteria for diagnosis are discussed.
Assuntos
Cisto do Úraco , Adulto , Humanos , Masculino , Tomografia Computadorizada por Raios X , Cisto do Úraco/complicações , Cisto do Úraco/diagnóstico , Cisto do Úraco/epidemiologiaRESUMO
The suggestion that the biological response to an oily intramuscular injection of testosterone ester is regulated by rapid accumulation of the steroid in body fat, followed by a slow release, has been tested by comparing the release rates of 14C-labelled testosterone propionate from different solvents following intramuscular injection into rats. Disappearance from the injection site was rectilinearly related to in-vitro partition coefficients, but elimination of radioactivity in urine and faeces was significantly longer, and the same for all four solvents. Testosterone and testosterone propionate were found in equal concentration in body fat, 2 and 3 days after injection, but their concentrations were too low to form an effective depot. It is suggested that the delay in release, and the independence of the delay on the nature of the solvent is a consequence of biliary recycling of testosterone.
Assuntos
Solventes/farmacologia , Testosterona/metabolismo , Tecido Adiposo/metabolismo , Animais , Disponibilidade Biológica , Radioisótopos de Carbono , Meia-Vida , Injeções Intramusculares , Masculino , Músculos/metabolismo , Próstata/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Glândulas Seminais/efeitos dos fármacos , Solventes/administração & dosagem , Testosterona/administração & dosagem , Testosterona/farmacologiaRESUMO
The granuloma-tissue formation inhibiting activity of various fractions of an extract of the aerial parts of Withania somnifera were established using subcutaneous cotton-pellet implantation in rats. Antiinflammatory activity was retained in the methanolic fractions of the plant extract and was comparable to that of a 5 mg/kg dose of hydrocortisone sodium succinate. Activity was attributed to the high content of biologically active steroids in the plant, of which withaferin A is known to be a major component.
Assuntos
Granuloma/tratamento farmacológico , Extratos Vegetais/farmacologia , Glândulas Suprarrenais/efeitos dos fármacos , Animais , Gossypium , Tecido de Granulação/efeitos dos fármacos , Tecido de Granulação/patologia , Granuloma/patologia , Iraque , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
Five plants (Myrtus communis, Apium graveolens, Matricaria chamomilla, Withania somnifera and Achillea santolina) grown in Iraq were assessed for their anti-inflammatory activity on intact rats by measuring the suppression of carrageenan-induced paw edema produced by 1/10 of the intraperitoneal LD50 doses for the respective 80% ethanol extracts. Acetylsalicylic acid was used as the standard drug. Results showed that the plants possessed varying degrees of anti-inflammatory activity and were classified in the following descending order of activity: W. somnifera greater than A. graveolens greater than A. santolina greater than M. chamomilla greater than M. communis.
Assuntos
Anti-Inflamatórios/farmacologia , Plantas Medicinais , Animais , Carragenina , Edema/induzido quimicamente , Edema/tratamento farmacológico , Feminino , Iraque , Dose Letal Mediana , Masculino , Pletismografia , Ratos , Ratos EndogâmicosRESUMO
A new crystalline form and a solvate of glibenclamide were prepared and characterized by hot-stage microscopy, DSC, IR, scanning electron microscope, X-ray powder diffraction and dissolution studies. From I, III and the solvate which melt at 174.4, 153.2 and 109.3 degrees C, were obtained by crystallization. Significant differences between the three forms in the X-ray and IR spectra were observed. Polymorphic transformation was observed for the least stable form (III) to the most stable one (form I) upon storage at different temperatures and trituration. The dissolution profiles showed significant differences between the three forms, with form III having the highest dissolution rate.